15/02/2026
💡 Light Dependent Resistor (LDR):
A Light Dependent Resistor (LDR), also called photoresistor, is a special type of resistor whose resistance changes automatically with the intensity of light falling on it.
An LDR is a passive electronic sensor that detects light.
📌 More light → Lower resistance
📌 Less light (darkness) → Higher resistance
Working Principle
The working of an LDR is based on the principle of photoconductivity. When light photons hit the semiconductor surface, they release electrons. More free electrons mean better conductivity.
So, the resistance decreases as light intensity increase
🌍 Common Applications of LDR
✅ Automatic Street Light Control
✅ Solar Garden Lamps
✅ Light Intensity Measurement
✅ Camera Exposure Control
✅ Burglar Alarm Systems
✅ Smart Home Lighting Automation
✅ Day/Night Switching Circuits
